Applying protective coatings



influences of ground and hitherto failed because in favourableconditions,

Patented Aug. 19, 1924.

UNITED STATES "PATENT OFFICE.

JOSEF VON VASS, 0F BUDAPEST, HUNGARY.

APPLYING rno rnomrvn conrmes.

No Drawing.

certain new and useful Improvements in Applying Protective Coatings, ofwhich the following is a specification.

invention refers to protective coatings for rendering foundation pits,galleries, walls and the like leak-proof, and more particularly to amethod of preparing and applying coatings which are proof againstliquids and acids.

It is a well-known fact that ground water, and waste water (tail water)containing impurities and salts, have so detrimental an effect uponconcrete constructions that concrete is avoided in tunnel and canalconstructions in spite of the extraordinary advantages it offers.

All endeavours to provide concrete with a reliable insulation againstthe detrimental Waste water have the majority of cases it was notpossible to apply the waterproof coating to the outer surface of thebuilding, as, for instance, a tunnel or large canal, in a manner freefrom objections. For hitherto it was customary first to build theconcrete construction which was then left exposed, without any kind ofprotection, to the destructive influences both chemical and mechanical,of the ground water during the critical period of setting, i. e., aperiod when it actually had the greatest need of protection, theconcrete thus becoming veritably saturated with ground and Waste water."

Only afteFhaving set under the most unendeavours were then made toprotect the concrete by means of acid-proof and water-proof coatings. Itis, however, perfectly clear that these coatings could not ofler anyresistance worth mentioning against mechanical influences of somestrength such as water pressure in view of the fact that these coatingshad to be applied to fresh, wet concrete to which they could not adherefirmly. Conseqently the concrete was destroyed after a short time inspite of all precautions and insulations. I

According to my invention, now, these drawbacks are remedied byproviding not the concrete construction, but the foundation pit (trench)or gallery shaft itself with a Application filed October 14, 1920.Serial No. 417,029.

protective coating or layer of asphalt capable of resistance against'thechemical and mechanical influences described above, whilst at the sametime having constructional strength and having a water-proofing effect.

The detrimental influences of ground and drain water are avoided by thismeans, and more especially the fresh concrete. is protected during thesetting period. For just this protection of the fresh concrete is themost important point to be achieved on account of the fresh concretebeing far more liable to detrimental influences, both mechanical as wellas chemical than old concrete which has already set.

In order however, to achieve this purpose, it is of importance that theasphalt or tar concrete should be applied quickly and in thicker orthinner layers corresponding to the irregularities of the foundationpit, shaft or gallery, it being of greatponsequence that the materialapplied penetrate deeply into all recesses, cracks and joints, thusproducing a really water-proof insulation.

Asphalt or tar concrete can, owever, only comply with these demands, ifit is not rammed in layers, but deposited on the surface of thefoundation pit, shaft or gallery, in accordance with my invention, byblowing it onto the surface in question and into the cracks and jointsin sprayed condition and under high pressure, after which it is stillpossible to fill up gaps or rubble stone containing water, behind thefoundation pit now closed-off in a waterproof manner, with asphalt ortar concrete by forcing the liquid material into-the cavities after somemethod already known in itself.

I am aware that paints and even cement concrete and lime-mortar havealready been blown onto surface under the form of sprays, however thepur ose of my invention can onl be achieved y means of an acid-proof aspalt or tar concrete.

No method of applying such material by spraying has as would scarcely befeasible to practice it with the contrivances known up to date.

In'practicingm invention I may for the inst. proceed as f0 lows:

In a receptacle fitted with a stirring device and containing two or morechambers allowin of recharging with material during wor 'ng by a systemof looks or gates, the asphalt is mixed with the desired addiyet beendevised and it tional or diluting substances and then pressed by meansofcompressed air to a nozzle right at the place of employment through aflexible tube. In order to reduce the asphalt mixture to the liquidstate and maintain it thus, the receptacle may be heated by a source ofheat of some suitable kind and hotcompressed air may be introduced intothe asphalt mixture in fine subdivision bymeans of perforated pipeslocated on the bottom of the receptacle, the compressed air not onlymixing the asphalt material but also heating it rapidly, rendering itliquid and feeding it to the nozzle intimatel mixed, with hot air.

Be ore or after escaping from the nozzle, the material is preferablyfurther also converted into spray by means of hot compressed aircontaining large quantities of solid material such as sand and the-like,admixed to :it, the spray being blown onto the working surface, or'intothe joints and chinks thereof, respectively, under a pressure preferablyamounting to about two atmospheres.

Spraying the as, halt or tar material already mixed with hot compressedair, by aid of hot compressed air containing large quantities of sandand other solid admixtures, results in the formation of a concrete, theasphalt or tar material solidifying rapidly after being blown on.

0 this end the material is filled into a receptacle likewise providedwith looks or gates and consisting of two or more chambers, the saidreceptacle being connected with the nozzle by a second hose conduit.Through this hose pipe the compressed air conducts lar e quantities ofsand which may be controlled in regard to quantity as may be desired, sothat the sand meets with the liquid tar or asphalt material respectivelyeither within, before or behind the nozzle and after having beenthoroughly mixed therewith, is blown against the surface to be protectedor the floor and walls respectively, of the pit or the gallery there tosolidify and set.

I may, however, also proceed so as to first mix the sand, clay, andother material with ground asphalt, tar or some other bituminous productin powdered condition this dry mixture then being conducted underpressure through a flexible pipe from a corresponding receptacle withthe aid of hot or cold compressed air to a nozzle, hot compressedairbeing simultaneously introduced into the nozzle in order to heat theasphalt or bituminous product added to the mixture either within,before, or after its exit from the nozzle, whereupon the mixture whichis now capable of settling, is blown under-the form of a spray onto theworking surface, where it then solidifies and forms the desired asphaltconcrete.

An important feature of this method consists in the fact that theformation of the mortar takes. place by the application of hotcompressed gases.

However, if tar or asphalt products of corresponding fluidity orsuitable means of solution and dilution are employed, the heating of thetar or asphalt as well as the employment of hot com ressed air can ofcourse be dispensed with.

The granular material such as sand, ground, clay and the otheradmixtures can also be fed to the receptacle ready-mixed with the tar orasphalt products which may either be fluid, or viscid, or powdered, thematerial then being conducted to the site of work under pressure througha hose-pipe by aid of hot compressed air, sufficient heat for theformation of the concrete being gained by enlisting the collaborationofv the friction caused in the hose pipe. In this case as well thematerial is sprayed onto the working surface through a nozzle ofsuitable design, owing to the compressed air expanding on leaving thenozzle and thus disinte rating the material.

This modification offers the advantage that the operator need onlyhandle a single hose and therefore works with reater facility andreliability than in hand ing two hose pipes, one for granular materialand one for tar, both jets meeting in the nozzle just before their exitfrom the same. Moreover, the necessity of continually regulating thesupply of liquid material is done away with, the operator thus beingenabled to pay more attention to the surface he is operating upon.

I may even mix the tar or asphalt products with clay alone, thusobtaining a very pliable product which is impervious to water andtherefore particularly suitable for the insulation of tunnels andshafts, rovided it be pressed in whilst in the p astic or powderedstate, inasmuch as in both cases a homogeneous mass is formed which isnot interrupted by layers.

Preferabl powdered clay or lime, or both, or other a mixtures such asfibrous materials are admixed to the sand and extraordinarily highdensity, strength and toughness are achieved in this manner.

It is obvious that other methods, such as for instance laying on theasphalt concrete with a trowel, or ramming and pressing it into thechinks, could never be equally successful, on account of the sprayedmaterial being far denser, besides penetrating deeply even into thenarrowest cracks an being easily kept at a uniform temperature inaccordance with its particular urpose, a thing which is absolutelyimpossi le in the case of manual labour.

In employing this method not only the final result turns out to be farsuperior to the results of manual work but it is actually the onlyfeasible method, and the cheapest one at that, for applying asphaltconcrete to the external walls of the foundation pit or gallery in areliable way and with any desired thickness and moreover rapidly in sucha manner as to progress with the buildmg.

In case that an increased leak-proofness of the foundation pit or thegalle should be desired, I prefer pressing aspha t or tar concrete intothe chinks and cavities orin the case of dumpsinto the rubble stone,either before or after laying on the asphalt concrete, this beingperformed by tappin the walls at the corresponding points an distancesand fitting tubes into these holes, the tubes then being connected withthe receptacle containing the tar or asphalt, as described above, bymeans of pipes or hoses and by then pressing the tar or asphalt into thecavities with the aid of pumps or compressed air, after havingpreviously blown through and warmed these cavities as far as possiblewith hot compressed air in order to prevent the material being pressedin, from solidifying prematurely.

Corresponding to the purpose, ample quantities of sand and powdered clayor other materials are also mixed with the asphalt or bitumen concreteemployed for pressing in.

Obviously the novel method can be employed with equal advantage in allcases where it is desirable to lay on a thick layer which is impervioust water. It is applicable in the case of walls, ceilings, tanks of allkinds, pillars and the like, and for the interior or exterior coatingsof conduitpipes, all these objects thus being protected againstdetrimental chemical influences.

I claim:

1. The method of waterproofing surfaces which consists in spraying ontothe surface to be protected a mixture of plastic bituminous material andsolid granular material so as to force said mixture into the surfaceinterstices.

2. The method of waterproofing surfaces which consists in spraying ontothe surface to be rotected a hot mixture of bituminous material andsolid granular material so as to force said mixture into the surfaceinterstices.

3. The method of waterproofin surfaces which consists in spraying onto te'surface to be protected a hot mixture of bituminous material, solidgranular material and compressed gas.

4. The method of waterproofing surfaces which consists in spraying ontothe surface to be protected a mixture of bituminous material, solidgranular material and hot compressed gas.

5. The method of waterproofing surfaces which consists in spraying ontothe surface to 'be protected a mixture of asphalt, clay and hotcompressed gas.

6. The method of waterproofing surfaces which consists in mixing a jetof bituminous material and hot compressed gas, and a jet of solidgranular material and hot compressed gas and directing the combined jetsonto the surface to be protected.

7. The method of waterproofing surfaces which consists in blowing hotair into the cavities and joints of a wall and then spraying onto saidwall a hot mixture of bituminous material solid granular material andcompressed air.

8. The method of waterproofing surfaces which consists in mixing a jetof dry bituminous material and a mineral substance with a jet of hotcompressed gas and directing the combined jets onto the surface to berotected.

9. 'l he method of waterproofin surfaces which consists in spraying ontot e surface to be protected 3, mixture of liquid bituminous material,solid granular material and compressed gas.

10. The method of waterproofing surfaces which consists in injecting hotair into bituminous material, pressing the plastic mixture of bituminousmaterial and air through a pipe, mixing it with a mixture of compressedair and solid granular material and spraying the final mixture into thesurface t be protected.

In testimony whereof I aflix my signature.

J OSEF VON VASS.

